Mr. Clapper says China is “leading suspect” in the theft of millions of personnel records

WASHINGTON—The top U.S. intelligence official signaled Thursday that Chinese hackers were behind the theft of millions of personnel records from the federal government, marking the administration’s most pointed assignment of blame since the breach was announced June 4.

Director of National Intelligence James Clapper, speaking at a Washington intelligence conference, said China was the “leading suspect” in the attacks, adding that given the difficulty of the intrusion, “You have to kind of salute the Chinese for what they did.”